1. Field of the Invention
The present invention relates to an apparatus for recycling metal scraps, and more particularly, to an apparatus for recycling metal scraps that can convert the scraps, produced in the machining of a metal material, into a solid compact having a high specific gravity, so that the scraps are not lost due to oxidation when they are being melt, and convert the scraps without using cutting fluid, thereby reducing the creation of pollutants.
2. Description of Related Art
The process of cutting a metal material produces various types of scraps, such as granular or spiral scraps. The scraps take a sizable amount, which is typically 5 to 10% of the weight of the metal material subjected to the cutting. Therefore, various methods are used to collect and recycle the scraps. For example, as for scraps produced in the cutting of a cast material, the scraps are melted again together with a molten source metal in a melting furnace, so that it can be reused as a raw material in the casting.
However, the collected scraps, which are input into the melting furnace, have a significantly small specific gravity relative to the molten source metal, so that the majority of scraps input into the melting furnace suspends on the surface of the molten metal without immersing into the molten metal while it is being melted. Thus, a great amount of the scraps is oxidized in the melting process by contact with air. Since the oxidized scraps lost their own properties of a source metal, they are screened and disposed. Thus, only 50% to 60% of the input scraps can be reused, thereby raising a problem such as a very low source recovery rate (recycling rate).
To solve this problem, a method had been proposed, in which the molten metal is rotated to make the input scraps immerse more easily in the molten metal, thereby reducing the loss of scraps due to oxidation. However, in order to use this method, special equipments for rotating the molten metal are required and a melting furnace should be separately fabricated to suit to the equipment, so that mounting costs for a melting apparatus increase greatly. Furthermore, the rotation of the molten metal results in a reduction in the lifetime of the melting furnace and an increase in the cost of energy that is consumed in the process.
Further, while there had been proposed a method that the suspended scraps on the surface of the molten metal are forcedly pushed and immersed in the molten metal, a problem also arises in that special equipments for immersing the scraps are required and an installation cost for a melting apparatus increases greatly, and for small, light scraps, it is difficult to immerse them in the molten metal, so that the effects of reducing losses of the scraps due to oxidation are degraded.
Meanwhile, the recovered scraps are impregnated with cutting fluid that is used for cutting a metal material. However, if the scraps impregnated with the cutting fluid are melted as they are, an environmental contamination arises due to combustion of the cutting fluid. To prevent this, according to the related art, a separate washing process for removing the cutting fluid was required. However, because of a large surface area of the scraps, a great amount of cost and time was taken in the washing process, resulting in a further deterioration in a recovery efficiency of the scraps.
The information disclosed in this Background of the Invention section is only for the enhancement of understanding of the background of the invention, and should not be taken as an acknowledgment or any form of suggestion that this information forms a prior art that would already be known to a person skilled in the art.